150 likes | 749 Views
EVAPORATIVE EMISSIONS CONTROL SYSTEMS. Chapter 8 Classroom Manual Page 244 Lab Manual Page 328. CBC AUTOMOTIVE RK. OBJECTIVES. Describe the operation of an evaporative (EVAP) control system during the canister purge and non purge modes. Diagnose & service evaporative systems.
E N D
EVAPORATIVE EMISSIONS CONTROL SYSTEMS • Chapter 8 • Classroom Manual Page 244 • Lab Manual Page 328 CBC AUTOMOTIVE RK
OBJECTIVES • Describe the operation of an evaporative (EVAP) control system during the canister purge and non purge modes. • Diagnose & service evaporative systems. • Use scan tester to diagnose EVAP systems. • Diagnose EVAP system thermal vacuum valves CBC AUTOMOTIVE RK
EVAP SYSTEMS • Gasoline (Hydrogen and Carbon) HC is a pollutant and must not be allowed to escape to the atmosphere. • Purpose of EVAP is to contain vapors from fuel tank and carburetor when engine is off. • Burn vapors in engine when warmand under cruise conditions. CBC AUTOMOTIVE RK
SYSTEM DESIGNS • Main components are the charcoal canister, purge valve, rollover valve, lines. • Two types of EVAP systems • Mechanical - Vacuum controlled • Computerized - Electrically controlled CBC AUTOMOTIVE RK
246C CHARCOAL CANISTER • Typical canister in vapor storage mode. • Absorbs vapors from carburetor and fuel tank CBC AUTOMOTIVE RK
245C PURGE VALVES • Ford Purge valves. • Typically normally closed • Purges above idle CBC AUTOMOTIVE RK
245C ROLLOVER VALVE • Located in top of the fuel tank. CBC AUTOMOTIVE RK
OBD II Evaporative Emission System Monitor • Tests ability of fuel tank to hold pressure • Tests ability of purge system to vent vapors from charcoal canister • Detects leaks and restrictions is EVAP system • Fuel tank will cause MIL light to come on.